The present invention relates to combining elements into subarrays. In particular, the outputs of different groups of elements are combined to form subarrays for ultrasound imaging.
Signals from different elements are combined to form subarrays. The use of subarrays may minimize the number of receive beamformer channels used in an ultrasound imaging system or the number of cables to communicate the signals from the elements to the ultrasound imaging system. For example, a two-dimensional transducer array is divided into a number of pre-set subarrays. Signals from elements within a same subarray are combined together and transmitted through a cable to an ultrasound imaging system. The number of subarrays corresponds to the number of cables and receive beamformer channels of the imaging system. However, a different transducer design and associated subarray combinations may be needed for systems with different numbers of receive beamformer channels to provide similar imaging performance. Providing different electronics or transducer arrays is expensive. Alternatively, less than all of the elements are used where an imaging system has fewer receive beamformer channels than subarrays. This reduction in aperture may result in lower resolution or lower performance imaging.
U.S. application Ser. No. 10/741,827 filed Dec. 19, 2003 and U.S. application Ser. No. 10/741,538 filed Dec. 19, 2003, the disclosures of which are incorporated herein by reference, disclose altering the size of subarrays as a programmable trade off between the number of transducer array elements and the number of receive beamformer channels. The size, shape or location of subarrays may be dynamically varied. Electronics are provided in the transducer assembly for implementing the subarray variation. The electronics provide time division multiplexing or partial beamforming for the subarrays. The electronics allow variation in subarray size for use with a same ultrasound imaging system.